The Latin names and authority of the new cultivar described and disclosed herein is Acer truncatum Bunge, commonly known as Shantung maple, Shundong maple, or purple-blow maple.
The genus Acer comprises a diverse group of temperate-zone deciduous and evergreen trees and/or shrubs, commonly called “maple(s).” Acer truncatum, introduced into cultivation in 1881, is only now being considered more widely as an ornamental, deciduous landscape tree, and small-sized street tree. Acer truncatum is native to northern and northeastern China, and also far eastern Russia, the Korean peninsula, and Sakhalin Island.
Acer truncatum is classified within Acer Section Platanoidea, a subgeneric grouping of closely related maples that includes 10 species. Within this section are other familiar species, including Acer platanoides (commonly known as Norway maple) and Acer campestre (commonly known as hedge maple). However, Acer truncatum is not closely related to Acer saccharum (commonly called sugar maple), despite the superficial resemblance of the leaves of these 2 species. Unlike Acer saccharum, Acer truncatum is most readily distinguished by its white, latex-bearing sap (a trait of all species of Acer Section Platanoidea) and its spring growth flush that is variously colored in bronze to orange to reddish tones. Under cultivated conditions, Acer truncatum matures as a small-sized tree reaching up to 25 to 33 feet (7.5 to 10 m) tall and bearing a round-headed canopy. All three of these other maples, Acer platanoides, A. campestre, and A. saccharum, mature at substantially larger sizes than does A. truncatum. Only with great age can Acer truncatum reach heights comparable to those of medium- to large-sized trees, as specimens of 55 to 70 feet (16.5 to 21 m) are known in cultivation, and heights of 75 feet (23 m) have been reported from the wild. In cultivation in the U.S., Acer truncatum is highly regarded for its lack of susceptibility to any major pests, diseases, and insects. Acer truncatum is a widely adapted species that is cold hardy to USDA Zone 4 and also prospers in the heat of USDA Zone 9.
My new ‘WF-AT1’ variety originated in 1998 from sown seed that gave rise to a seedling plant growing in a field nursery block 5 miles west of Greenville, N.C. (Pitt County). The origin of the seed was from a commercial nursery, of true-to-type source, and was not from a pre-existing cultivar of Acer truncatum. Therefore, the seed source from which ‘WF-AT1″ is derived is based on an unpatented, undisclosed mother plant of Acer truncatum. Occurring in a seed-block, along with other trees of Acer truncatum, one tree stood out for its vigor, attractive foliage qualities throughout the growing season, and especially its flaming orange-red fall color. This tree was subsequently marked and held for further observation. Since 1998, this original tree of the ‘WF-AT1’ variety has grown to 19 feet (5.8 m) tall by 13.5 feet (4.1 m) wide and has a trunk diameter (dbh) of 6.75″ (17 cm), as of December, 2005. The ‘WF-AT1’ has been asexually propagated at my direction in Pitt County, N.C., via budding and grafting. This propagation and observations of the resulting progeny have proven the characteristics of my new variety to be firmly fixed and reproduce true to type. Furthermore, these observations have confirmed that my new variety represents a new and improved variety of Shantung maple tree.